In conventional compressor valves such as have been used for more than 100 years, an equilibrium of forces of spring forces and compressive forces at a closing body have the result that this closing body is moved away from the valve seat in the direction of flow. Closing bodies are usually plates, but can also be knobs. The fact is disadvantageous in this type of construction that the fluid has to flow around the closing body and in this respect undergoes a change of direction twice. This has the consequence that a larger pressure drop occurs at the valve and moreover has the effect that a narrow flow cross-section is formed along which the fluid has a high flow speed.
Document U.S. Pat. No. 6,149,400 discloses a conventional valve of plate-type construction. The movement of the plate can be influenced by an additional force from a magnetic coil so that the plate is moved in a delayed manner from the open position into the closed position. The above-described disadvantages remain present, however.
Document EP 0 971 160 B1 discloses an actively controlled valve for a piston compressor. The valve includes a valve plate which is rotatably supported with respect to a counter-plate either to open or to close a passage opening by rotation. The valve plate is in this respect moved directly by an external drive. The fact is disadvantageous in these known concepts that they can only be actuated slowly and imprecisely. Valves in accordance with documents WO 01/65157 and WO 01/59266 A1, which described a slightly modified form of the already described patent, have the same disadvantage.